What will determine the element of an ability, the quanta of the ability itself, or the quanta of the card the ability is on?
For instance, the improve of the fallen druid is on an entropy card, but the ability requires life. Which mark will reduce the cost of the ability?
At any rate, I'm not sure how much this would really be used, as it stands. Every other card played would save 1 quanta of your mark. The upgraded card would require 2 cards/abilities to be played to make up for the cost. The 3rd brings it equal to a tower, and the 4th would be worth it at 0 quanta, but be even after the turn, if you had quanta to spare.
In that respect, maybe it could help rush decks. However, I have a hard time seeing how this card would fit in outside of a rush, since, again, unless you are quanta starved, a tower would provide more quanta over time, and it would require several cards being played and abilities being used to match the tower, which is also more versatile in that it doesn't need to be played on the turn of several abilities/cards being used.
I could imagine it being used a bit more if ability costs are reduced based on the element of the card. One cost abilities are common, and paying 2 to get a "spash" for an ability could prove useful. Entropy and darkness come to mind right away; both have nice cards with good abilities that require a second element to pay for 1 quantum cost abilities, but even then, would it be worth the card space to let a pest burrow, and would you add a fallen druid to use its ability a few times, when a life pendulum (or mark) could provide more uses?
Even if the card is based on the card element, not the ability element, I am not sure the answer is yes.
Just my 2 cents for what its worth.
